Design and construction of the Gregoire Sanitary Sewer project in Fort McMurray posed significant risks and challenges. The continuous, 1.6 kilometre, 600 millimetre diameter, dual sanitary sewer system traversed a business area, soccer field, children’s play park, a busy roadway, and Highway 63—a major highway and the only transportation link to the oil sands development north of Fort McMurray. The sewer alignment included significant environmental and geological constraints.
Associated Engineering worked closely with the Municipality to develop a design and construction methodology employing horizontal directional drilling, a trenchless construction technique. Using trenchless construction, the sewer was installed in varying and steep terrain through an environmentally sensitive valley, over 50 metres deep, to avoid an actively sliding slope and protected waterway. Using this technical approach for such a long sewer over varying and complex terrain and to such significant depths was an innovative application of this technology.
The design and construction of the Gregoire Sanitary Sewer demonstrates the suitability of horizontal directional drilling for installing a long pipeline through varying and deep terrain to minimize impact on the environment, reduce construction risk, and reduce impact on the public.